<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >

    <item>
        <shape android:shape="rectangle" >
            <solid android:color="#aaaaaa" />
        </shape>
    </item>
    
    <item
        android:bottom="1px"
        android:left="1px"
        android:right="1px"
        android:top="1px">
        <shape android:shape="rectangle" >
            <solid android:color="#ffffff" />
        </shape>
    </item>
    
    
</layer-list>